YAMAHA YFZ450 2008 Owners Manual

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9. Check the O-rings for damage, and replace
them if necessary.10. Install a new oil filter element and the O-rings.NOTE:
Make sure that the O-rings are properly seated.
11. Install the oil filter element cover by installing
the bolts, and then tighten them to the speci-
fied torque.
1. Oil filter element cover
2. Bolt
1 2

1. Oil filter element
2. O-ring
Tightening torque:
Oil filter element cover bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1
2 2

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12. Install the crankcase engine oil drain bolt and
the engine oil tank drain bolt, and then tighten
them to the specified torques.
13. Pour the specified amount of the recommend-
ed engine oil through the engine oil tank filler
hole, and then install and tighten the engine oil
tank filler cap.
14. Pour the specified amount of the recommend-
ed engine oil through the crankcase engine oil
filler hole, and then install and tighten the
crankcase engine oil filler cap.NOTE:

Be sure to wipe off spilled oil on any parts after the
engine and exhaust system have cooled down.CAUTION:

ECB00300

In order to prevent clutch slippage (since the
engine oil also lubricates the clutch), do not
mix any chemical additives. Do not use oils
with a diesel specification of “CD” or oils of
a higher quality than specified. In addition,
Tightening torques:
Crankcase engine oil drain bolt:
20 Nm (2.0 m·kgf, 14 ft·lbf)
Engine oil tank drain bolt:
19 Nm (1.9 m·kgf, 14 ft·lbf)
Recommended oil:
See page 10-1.
Oil quantity:
Without oil filter element replacement:
Quantity in oil tank:
1.55 L (1.64 US qt) (1.36 Imp.qt)
Quantity in crankcase:
0.20 L (0.21 US qt) (0.18 Imp.qt)
With oil filter element replacement:
Quantity in oil tank:
1.55 L (1.64 US qt) (1.36 Imp.qt)
Quantity in crankcase:
0.30 L (0.32 US qt) (0.26 Imp.qt)

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do not use oils labeled “ENERGY CONSERV-
ING II” or higher.

Make sure that no foreign material enters the
crankcase.
15. Start the engine, and then let it idle for several
minutes while checking it for oil leakage. If oil
is leaking, immediately turn the engine off and
check for the cause.
16. Turn the engine off, and then check the oil lev-
el and correct it if necessary.
17. Install the engine guard by installing the bolts,
and then tighten them to the specified torque.
CAUTION:

ECB00370
Be sure to apply LOCTITE® to the engine
guard bolts before installing them.
EBU23470
Coolant
The coolant level should be checked before each
ride. In addition, the coolant must be changed atthe intervals specified in the periodic maintenance
and lubrication chart.
EBU23490
To check the coolant level
1. Place the ATV on a level surface.
NOTE:

The coolant level must be checked on a cold en-
gine since the level varies with engine tempera-
ture.
2. Check the coolant level in the coolant reser-
voir.
NOTE:

The coolant should be between the minimum and
maximum level marks. Tightening torque:
Engine guard bolt:
7 Nm (0.7 m·kgf, 5.1 ft·lbf)

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3. If the coolant is at or below the minimum level
mark, remove panel A. (See page 8-9.)
4. Remove the reservoir cap, add coolant or dis-
tilled water to the maximum level mark, install
the reservoir cap, and then install the panel.CAUTION:
ECB00400

If coolant is not available, use distilled water
or soft tap water instead. Do not use hard wa-
ter or salt water since it is harmful to the en-
gine.

If water has been used instead of coolant, re-
place it with coolant as soon as possible,
otherwise the engine may not be sufficiently
cooled and the cooling system will not be
protected against frost and corrosion.

If water has been added to the coolant, have
a Yamaha dealer check the antifreeze con-
tent of the coolant as soon as possible, oth-
erwise the effectiveness of the coolant will
be reduced.
NOTE:

If the engine overheats, see page 8-52 for further
instructions.
EBU23560
To change the coolant
WARNING

EWB01890
Wait for the engine and radiator to cool before
1. Maximum level mark
2. Minimum level mark
3. Coolant reservoir
4. Coolant reservoir cap
Coolant reservoir capacity (up to the maximum
level mark):
0.29 L (0.31 US qt) (0.26 Imp.qt)
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removing the radiator cap. You could be
burned by hot fluid and steam blown out under
pressure. Always place a thick rag over the cap
when opening. Allow any remaining pressure
to escape before completely removing the cap.
1. Place the ATV on a level surface.
2. Remove panel A. (See page 8-9.)
3. Place a container under the engine, and then
remove the coolant drain bolt. (Use a trough
or a similar object as shown.)
4. Remove the radiator cap.5. Remove the coolant reservoir by removing the
bolts.
6. Remove the coolant reservoir cap, and then
turn the coolant reservoir upside down to
empty it.
1. Coolant drain bolt
2. Trough
2 1

1. Radiator cap
1

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7. After draining the coolant, thoroughly flush the
cooling system with clean tap water.
8. Install the coolant reservoir by installing the
bolts.
9. Replace the coolant drain bolt washer if it is
damaged, install the coolant drain bolt, and
then tighten it to the specified torque.10. Pour the recommended coolant into the reser-
voir to the maximum level mark, and then in-
stall the reservoir cap.
11. Pour the recommended coolant into the radia-
tor until it is full.CAUTION:
ECB00400

If coolant is not available, use distilled water
or soft tap water instead. Do not use hard wa-
ter or salt water since it is harmful to the en-
gine.

If water has been used instead of coolant, re-
place it with coolant as soon as possible,
1. Coolant reservoir cap
2. Coolant reservoir
3. Bolt
Tightening torque:
Coolant drain bolt:
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
1 3
2

Antifreeze/water mixture ratio:
1:1
Recommended antifreeze:
High-quality ethylene glycol antifreeze con-
taining corrosion inhibitors for aluminum en-
gines
Coolant quantity:
Radiator capacity (including all routes):
1.30 L (1.37 US qt) (1.14 Imp.qt)
Coolant reservoir capacity (up to the maxi-
mum level mark):
0.29 L (0.31 US qt) (0.26 Imp.qt)

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otherwise the engine may not be sufficiently
cooled and the cooling system will not be
protected against frost and corrosion.

If water has been added to the coolant, have
a Yamaha dealer check the antifreeze con-
tent of the coolant as soon as possible, oth-
erwise the effectiveness of the coolant will
be reduced.
12. Install the radiator cap, start the engine, let it
idle for several minutes, and then turn it off.
13. Remove the radiator cap to check the coolant
level in the radiator. If it is low, add sufficient
coolant until it reaches the top of the radiator,
and then install the radiator cap.
14. Start the engine, and then check for coolant
leakage.
NOTE:

If any leakage is found, have a Yamaha dealer
check the cooling system.
15. Install the panel.
EBU23702
Cleaning the air filter element
The air filter element should be cleaned at the in-
tervals specified in the periodic maintenance andlubrication chart. Clean the air filter element more
frequently if you are riding in unusually wet or dusty
areas.
NOTE:

There is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
the hose and clean the air filter element and air fil-
ter case.
1. Remove the seat. (See page 4-11.)
2. Remove the air filter case cover by unhooking
the holders.
1. Air filter case check hose
1

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3. Loosen the wing bolt.
4. Remove the air filter element together with the
wing bolt and washer.5. Remove the wing bolt and washer from the air
filter element.
6. Remove the sponge material from the air filter
element frame.
1. Air filter case cover
2. Air filter case holder
2 1

1. Wing bolt
2. Sponge material
1 2

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7. Wash the sponge material gently but thor-
oughly in solvent.
WARNING

EWB01940
Always use parts cleaning solvent to clean the
sponge material. Never use low-flash-point
solvents or gasoline to clean the sponge mate-
rial because the engine could catch fire or ex-
plode.
8. Squeeze the excess solvent out of the sponge
material and let it dry.CAUTION:

ECB00440
Do not twist the sponge material when squeez-
ing it.
9. Check the sponge material and replace it if
damaged.
10. Apply a quality foam air filter oil to the sponge
material.
NOTE:

The sponge material should be wet but not drip-
ping.
11. Pull the sponge material over the air filter ele-
ment frame.
1. Sponge material
2. Air filter element frame
1 2

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12. Install the washer onto the air filter element
frame, and then insert the wing bolt into the
hole in the air filter element frame.
CAUTION:

ECB00451
Be sure to install the washer with the bent edge
facing outward as shown.
13. Insert the air filter element into the air filter
case, and then tighten the wing bolt.
14. Install the air filter case cover by hooking the
holders onto the air filter case.
15. Install the seat.
NOTE:

The air filter element should be cleaned every 20–
40 hours. It should be cleaned and lubricated more
often if the ATV is operated in extremely dusty ar-
eas. Each time the air filter element maintenance
is performed, check the air inlet of the air filter case
for obstructions. Check the air filter case rubber
joint to the carburetor fittings and the rubber joint
manifold fittings for an air-tight seal. Tighten all fit-
tings securely to avoid the possibility of unfiltered
air entering the engine.
CAUTION:

ECB00460

Make sure that the air filter element is prop-
erly seated in the air filter case.

Never operate the engine with the air filter el-
ement removed. This will allow unfiltered air
to enter the engine, causing rapid engine
wear and possible engine damage. Addition-
ally, operation without the air filter element
will affect carburetor jetting with subsequent
poor performance and possible engine over-
heating.
1. Washer
1